In both countries legal reforms were set by the killings, though more directly in Japan than in Britain. The lowering of the age of criminal responsibility to 14 in Japan was a direct result of the killing of Jun Hase. In Britain the killing of James Bulger was one of the sources of justification for more punitive legislation on juvenile offenders, most immediately in the 1994 Criminal Justice and Public Order Act. The longer term effects in Britain were less predictable, and came not from legislation but from rulings by judges in British courts and in the European Court of Human Rights. Both cases, therefore, had a symbolic and symptomatic status that had the power to motivate substantial changes at the level of national law. Both were held to signify problems in society at large, of failures in the education system, in family life, and in the socialization of children. Both revealed a loss of faith in experts, particularly experts in treatment, but also in the police and judiciary. In 1993, in Merseyside, England, two 10-year olds were arrested and charged with the abduction and murder of a 2-year old boy, James Bulger. In Kobe, Japan, in 1997, a 14-year old boy was arrested for the murder of an 11-year old boy, Jun Hase. This paper describes and analyzes the public and political responses to these two notorious cases of the killing of children by children. It discusses the way in which the cases were presented as symptomatic of wider social problems, and how in both Britain and Japan they acted as a catalyst for changes in the juvenile criminal justice system. Notes, references